YouTube doesn't work on home Internet

I have T-Mobile 5G cellular service and I also have T-Mobile 5G Home Internet service, and  I have found that T-Mobile appears to have some network problem in that it will not connect reliably with certain web sites and services.  More specifically, my devices will not connect reliably with YouTube or the Google Play Store using either the T-Mobile Home Internet or the T-Mobile 5G cellular network.  Most other web sites and services have no problem, although there may be others that do have a problem that I have not discovered.

I cannot connect with my new Pixel 6 phone to either YouTube or Google Play Store using either the cellular network or my Home Internet service.  I am a new customer to T-Mobile and have had T-Mobile service for about 2 weeks.  I do not believe (but am not totally sure) that these problems existed during my first week of service, but only seemed to appear in the last week.

The problem is not unique to my Pixel 6.  My older phone, a Pixel 2XL, has the same problem when connecting to my T-Mobile home internet.  I also have an older Apple iPhone 6 which also experiences the same problem on T-Mobile Home internet.  The latter two phones do not have cellular service, so I cannot say for sure what would happen if connected through the T-Mobile cellular network, but suspect they would have problems as well.

I also have Xfinity Home Internet which I was hoping to replace with the T-Mobile Home Internet.  When I turn off the T-Mobile Home Gateway and turn on the Xfinity Gateway, I have no problems.  This would seem to effectively isolate the problem to the T-Mobile network.

The connectivity problem on the T-Mobile cellular network exists near my home, but I have also tried it in other parts of the western suburbs of Chicago and it has the same problem in the few other locations I have tried to use it.

This does not appear to be a wireless radio connection problem, as both the T-Mobile cellular service and the T-Mobile home internet service test out reliably using the Ookla Speedtest app at around 300 Mbit/sec download and about 40 Mbit/sec upload at my home location.  Furthermore, the T-Mobile cellular data connectivity and Home Internet connectivity work quite well with many other services including Amazon Prime Video and other streaming services.  So, it would appear that there is something blocking and throttling access to above mentioned web sites and services in the T-Mobile network.

I have called the T-Mobile support line and reported the problem but to no avail.  I was instructed to reboot my phone, reset the gateway, update my apps, all the usual first line support tactics.  None of these had any effect, and based on the symptoms and information above, you would not expect these to be effective.  This appears to be a network problem well above the level of support you can get on the phone.  No solution was promised and I am not sure of the status of my problem report.

Obviously, without access to Google Play Store and YouTube, T-Mobile access has a serious deficiency that needs to be corrected quickly for the T-Mobile service to be viable.

I would be happy to discuss my experience with any T-Mobile network engineer that would be willing to work on the problem.